Shock absorber



M. TIBBETTS June 24, 1930.

SHOCK ABSORBER Filed Nov. 28, 192:'

l i Le Patented June 24, 1930 UNETED STATS MILTON TIBBETTS, OF DETROIT,MICHIGAN, ASSIGNOR, TO PACKARD' MOTOR, (IAR COMPANY, OF DETROIT,MICHIGAN, A CORPORATION OIE' MICHIGAN I snoer: assomme Application ledNovember 28, 1927. Serial No. 236,046.

This invention relates to motor vehicles and particularly to shockabsorbing vmeans therefor. The invention relates more speciically tohydraulic shock absorbers of the vane piston type. y

In shock absorbers of this type there is always some small amount oflealrage of oil from the casing and usually an auxiliary reservoir orchamber is provided from -ivhich oil is drawn to supply the casing as itis needed. It is one of the objects of the present invention to soconstruct the casing and the auxiliary chamber that these parts may bemade tight and may be kept tight.

Another object of the invention is to simplify1 the construction of theparts both as to their form and to the machine Work re uired on them.

(inother object of the invention is to provide a simple connectingnieans from` the piston to the lower partV of the auxiliary chamber forwithdrawing oil lfrom the chamber for supplying the needs ofthe casing.

Other objects of the invention Will appear from the followingdescription taken in connection With the drawings, which forma part ofthis specification, and in which:V

Fig. 1 is a section through Vthe body of the shock absorber Inadeinaccordance with this invention, certain parts thereof being shown inelevation, the section being approximately on the 'line 1-1 of Fig. 2,and

Fig. 2 is a section substantially on the line 2 2 of Fig. 1.` L

The' support for the shock absorber is indicated at 10, this being aplate to 4Which the shock absorber is secured by tivo or more bolts 11.'The plate 10 is formed'ivith an opening 12 therein through which a partof the shock absorber projects, and a spacing washer 13 is provided sothat the shock absorber may be spaced slightly from the support toprovide clearance for its connecting boltsas Will hereinafter appear.V

The shock absorber proper comprises a casing 14 having an end Wall 15and a eentral boss 16, said boss having a bearing opening 17 therein.Theopposite end Wall of the casing is formed by a cover 18 Which has apart '19 extending intov the casing and forming an abutment for theinterior of the casing. rlhis cover is also formed with an outwardlyextending boss 2O having an opening 21 therein, in line with the opening17 of the casing. rlhe part 19 VWhich extends into the casing- `ishollowed out toV forni a chamber 22 and this chamber is enlarged andcompletely enclosed by a second cover or plate 23 which extends overAand is spaced from the cover. 18. Thus is provided a rather largeauxiliary chamber for an additional supply of oil for the shockabsorber.

The casing 14, the cover 18, and the second cover or plate23 are allthree secured together by several bolts 2li, in `addition to thetivobolts 11 above referred to. These bolts secure lthe parts togetherinsuch closev relationship that there can be no leakage to the outside atany point.

Within the casing is a shafty 25 upon which is a piston 26 preferablyformed as a part of the shaft, and this shaft is mounted in the bearingopenings 17 and 21 above referred to; One end of the shaft extendsentirelyY through the boss 16 and upon its outer end is an operating arm27 secured thereon as by a nut 28. Suitable packing is provided in theboss 16 and is held in place by a nut 29 on the boss.

The opposite end of theshaft 25 is mounts ed in the boss 20 and extendsthrough the opening 21 into the chamber y22. At least the end of theshaft is exposed to the `charnber and any leakage past the shaft will becaught in the chamber. Y

` The shaft 25 is drilled lengthwise as at 30 to form an oil conduit,and a passage 31 in the piston communicates with the conduit 30 and hascross passages 32`Which are provided. `with check valves 33 openingtowards the interior of thercasing. These check valves prevent the flowof Huid from the casing into the passage 31 but permit the fluid to flowfrom the passage 31 into the casing. Thus the passage 31 is alvvays opento the loiv pressure side of the piston and if there is any lack of oilat that side of the piston suction Will be created yin the passage 3land consequentlyl in the conduit 30.

Mounted upon the end of the shaft 25 that is exposed to the chamber 22is a pipe 34, this pipe having` an elbow and preferably threaded intothe end of the shaft so that it communicates with and forms acontinuation of the conduit 30. The pipe extends downwardly to near thebottom of the chamber 22 and is preferably vertically arranged, as shownin F ig. 2, when the piston 26 is in its intermediate position. As the.piston swings back and forth in the operation'of the shock absorber, thepipe 34 will of course swing with it, but it will always be adjacent thelower part of the chamber 22. The suction in the conduit 80 is of coursecommunicated to the pipe 34 and consequently when ever there is a lackof oil in the casing an additional supply will be drawn through the pipe34E, conduit 30 and passage 3l, from the chamber 22.

A by-pass and a metering plug 36 may be provided in the piston and shaftif desired, to permit the passage of a small amount of fluid from oneside of the piston to the other in order that too great a resistance tothe operation of the piston may not be created.

Also, `a check valve controlled by-pass 3T may be provided in the pistonif desired in order that greater resistance may be offered in onedirection than in the other.

It will be observed that the cover piece 18 is of very simple form,easily made of either a cored casting or a drop forging, ea silymachined, and easily ground, together with the casing 14, to form aclose fitting casing for the piston. 'Ihe second cover 23 maybe formedof a simple stamping and all of the parts are secured together to securethe greatest certainty against leakage.

While I have herein describedinsome detail a specific embodiment of myinvention, which I deem to be new and advantageous and may specificallyclaim, I do not desire it to be understood that my invention is limitedto the exact details of the construction, as it will be apparent thatchanges may be made therein without departing from the spirit or scopeof my invention.

Having thus described my invention, what I claim and desire to secure byLetters Patent is;

l. In a shock absorber. a casing, a piston in the casing, a. shaft forthe piston, an auxiliary supply chamber, and a tube on the shaftextending into said supply chamber.

2. In a shock absorber, a casing, a piston in the casing` a shaft forthe piston, an auxiliary supply chamber, and a pipe mounted on the shaftand adapted to oscillate therewith.

3. In a shock absorber, a casing, a piston in the casing, a shaft forthe piston, an auxiliary supply chamber, and a pipe connection mountedon the shaft and communicating with the casing through the piston.

4t. In a hydraulic shock absorber, the combination of a casing, a coverfor the casing, a piston operating in the casinff and having a shaftextending through t 1e cover, an auxiliary chamber beyond the cover, anda pipe on said shaft in said chamber.

5. In a hydraulic shock absorber, the combination of a casing, a covertherefor having' an opening therethrough, a chamber formed beyond thecover, a piston in the casing, a shaft for said pistonmounted in said,opening and conduit means extending from the chamber through theopening in the cover.

G. In a hydraulic shock absorber, the combination of a casing having acylindrical art and end walls, alined bearing openings through the endwalls, a piston in the cylindrical part of said casing and having a.shaft mounted in said bearing openings, said shaft extending through oneof said openings and having an operating arm on its outer end, and anauxiliary chamber into which the other end of said shaft extends.

7. In a shock absorber, the combination of a casing, a supply chamber, apiston in the casing having a shaft extending into but not through thesupply chamber, and means in the shaft and piston for withdrawing oilfrom the supply chamberA to the casing. n

8. In a shock absorber, the combination of a casing, an auxiliarychamber, a piston in the casing having a shaft extending into saidchamber, andA a pipe on said shaft extending to the lower part of saidchamber when the piston is in intermediate position.

9. Ina shock absorber, the combination of a casing, an auxiliarychamber, a piston in the .casing having a shaft, and means on theshaftfor withdrawing oil from the lower part of the chamber.

l0. Ina shock absorber, the combination of a casing, an auxiliarychamber, a piston in the casing, a pipe secured to the piston shaftandextending into the chamber, and means comprising a passageA and checkvalves in the piston communicating with said pipe for withdrawing oilfrom the chamber. Y

ll.`In a shock absorber, the combination of a casing having a centralopening in an end wall thereof, a piston in the casing having a shaftrmounted in and extending through said opening, a cover over the end walland shaft end to form a chamber, and means on the shaft extending to thelower part of the casing for withdrawing oil therefrom.

l2. In a hydraulic shock absorber, acasing, a` cover therefor having anopening therethrough, a piston operating in the casing having a shaftextending through the cover, a second cover for the casing bearing uponthe rst named cover and forming a chamber with the first named cover andthe end of the shaft, and conduit` means extending through the openingin the cover through which Huid from the chamber is moved to the casing.

13. In a shook absorber, a easing, a cover therefor having an openingtherethrough, a piston operating in the easing and engaging said cover,a shaft for thev piston extending through the cover and a second coverfor the casing bearing upon the first named cover and conduit meansextending through theV opening inthe cover.

14. In a hydraulic shook absorber, a easing having a Working chambertherein, a cover therefor having an opening therethrough, a pistonoperating in the Working chamber in the easing and engaging said cover,a shaft for the piston extending through the cover, a second cover forthe easing bearing upon the first named cover and extending over the rstnamed cover and over the shaft and conduit means eX- tending through theopening in the cover.

In testimony whereof` I aiX my signature.

MILTON TIBBETTS.

